// Copyright (c) 1996-99 The Regents of the University of California. All
// Rights Reserved. Permission to use, copy, modify, and distribute this
// software and its documentation without fee, and without a written
// agreement is hereby granted, provided that the above copyright notice
// and this paragraph appear in all copies.  This software program and
// documentation are copyrighted by The Regents of the University of
// California. The software program and documentation are supplied "AS
// IS", without any accompanying services from The Regents. The Regents
// does not warrant that the operation of the program will be
// uninterrupted or error-free. The end-user understands that the program
// was developed for research purposes and is advised not to rely
// exclusively on the program for any reason.  IN NO EVENT SHALL THE
// UNIVERSITY OF CALIFORNIA BE LIABLE TO ANY PARTY FOR DIRECT, INDIRECT,
// SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES, INCLUDING LOST PROFITS,
// ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF
// THE UNIVERSITY OF CALIFORNIA HAS BEEN ADVISED OF THE POSSIBILITY OF
// SUCH DAMAGE. THE UNIVERSITY OF CALIFORNIA SPECIFICALLY DISCLAIMS ANY
// WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE
// PROVIDED HEREUNDER IS ON AN "AS IS" BASIS, AND THE UNIVERSITY OF
// CALIFORNIA HAS NO OBLIGATIONS TO PROVIDE MAINTENANCE, SUPPORT,
// UPDATES, ENHANCEMENTS, OR MODIFICATIONS.

package org.tigris.gef.util;

import java.util.*;

public class PredicateStringMatch implements Predicate {

    // //////////////////////////////////////////////////////////////
    // constants
    public static int MAX_PATS = 10;

    // //////////////////////////////////////////////////////////////
    // instance variables
    String _patterns[];
    int _numPats;

    // //////////////////////////////////////////////////////////////
    // constructor
    protected PredicateStringMatch(String pats[], int numPats) {
        _patterns = pats;
        _numPats = numPats;
    }

    public static Predicate create(String pat) {
        pat = pat.trim();
        String pats[] = new String[MAX_PATS];
        int numPats = 0;
        if (pat.startsWith("*"))
            pats[numPats++] = "";
        StringTokenizer st = new StringTokenizer(pat, "*");
        // needs-more-work: support ? to match one character
        while (st.hasMoreElements()) {
            String token = st.nextToken();
            pats[numPats++] = token;
        }
        if (pat.endsWith("*"))
            pats[numPats++] = "";
        if (numPats == 0)
            return PredicateTrue.theInstance();
        if (numPats == 1)
            return new PredicateEquals(pats[0]);
        return new PredicateStringMatch(pats, numPats);
    }

    public boolean predicate(Object o) {
        if (o == null)
            return false;
        String target = o.toString();
        // System.out.println("[PredicateStringMatch] predicate: " + target);
        if (!target.startsWith(_patterns[0]))
            return false;
        if (!target.endsWith(_patterns[_numPats - 1]))
            return false;
        for (int i = 0; i < _numPats; i++) {
            String p = _patterns[i];
            int index = (target + "*").indexOf(p);
            if (index == -1)
                return false;
            target = target.substring(index + p.length());
        }
        return true;
    }

    // public static void main(String args[]) {
    // if (args.length <= 1) {
    // System.out.println("Arguments: pattern targets...");
    // System.out.println("outputs targets that match pattern");
    // System.out.println("be sure to protect pattern from shell expansion");
    // return;
    // }
    // System.out.println("Pattern = " + args[0]);
    // Predicate p = PredicateStringMatch.create(args[0]);
    // for (int i = 1; i < args.length; i++) {
    // if (p.predicate(args[i])) System.out.println(args[i]);
    // }
    // }

} /* end class PredicateStringMatch */
